一、SQL基础
1.查询
SELECT 列名称 FROM 表名称
2.去重
SELECT DISTINCT 列名称 FROM 表名称
3.WHERE 子句
SELECT 列名称 FROM 表名称 WHERE 列 运算符 值
4.AND 和 OR 运算符
SELECT * FROM User WHERE UserName='张三' AND UserID=10
5.ORDER BY 语句
SELECT OrgID, OrgName FROM Organization ORDER BY Company
6.INSERT
INSERT INTO 表名称 VALUES (值1, 值2,....)
7.Update
UPDATE 表名称 SET 列名称 = 新值 WHERE 列名称 = 某值
8.DELETE
DELETE FROM 表名称 WHERE 列名称 = 值
二、提升
1.IN 操作符多个值查询
SELECT column_name(s) FROM table_name WHERE column_name IN (value1,value2,...)
2.INNER JOIN 返回table_name1所有数据
SELECT column_name(s)
FROM table_name1
INNER JOIN table_name2
ON table_name1.column_name=table_name2.column_name
3.INNER JOIN 返回table_name2 和table_name1 交集数据
SELECT column_name(s)
FROM table_name1
LEFT JOIN table_name2
ON table_name1.column_name=table_name2.column_name
4.RIGHT JOIN 返回table_name2所有数据
SELECT column_name(s)
FROM table_name1
RIGHT JOIN table_name2
ON table_name1.column_name=table_name2.column_name
5.FULL JOIN
SELECT column_name(s)
FROM table_name1
FULL JOIN table_name2
ON table_name1.column_name=table_name2.column_name
6.SELECT INTO 复制表数据
SELECT * INTO table_name1 FROM table_name2
7.LIKE 模糊查询
SELECT column_name FROM table_name WHERE column_name LIKE '张%'
8.BETWEEN 某一个字段的值在哪个区间
SELECT column_name FROM table_name WHERE column_name BETWEEN value1 AND value2
9.TOP 查询数据库前几条数据
SELECT TOP 10 * FROM table_name
10.IS NULL/IS NOT NULL 查询某一个字段不为null
SELECT TOP 10 * FROM users where users_name is not null
SELECT TOP 10 * FROM users where users_name is null
三、函数
1.COUNT 查询表中总共有多少数据
SELECT COUNT( * ) FROM table_name
2.AVG 查询平均值
SELECT AVG(column_name) FROM table_name
3.MAX 查询某一字段最大值
SELECT MAX(column_name) FROM table_name
3.Min 查询某一字段最小值
SELECT Min(column_name) FROM table_name
4.SUM 对某一字段求和
SELECT SUM(column_name) FROM table_name
5.HAVING 子句 一般用于去重
SELECT Customer,SUM(qty) FROM Orders GROUP BY Customer HAVING SUM(qty)<100
6.FORMAT 时间格式转化
SELECT FORMAT(column_name,format) FROM table_name
四、实战
1.SELECT
1.FOR XML 将多条数据合并为一条数据
SELECT d.DriverName+','
FROM dbo.TaskDriver td WITH(NOLOCK)
INNER JOIN dbo.Driver d WITH(NOLOCK) ON td.DriverID=d.DriverID
WHERE td.IsValid=1 AND td.TaskID=384186 FOR XML PATH('')
2.FOR XML 加子查询加INNER JOIN 联合使用
SELECT A.RoleID,r.RoleName,LEFT(ColumnStr,LEN(ColumnStr)-1) AS ColumnStr
FROM(
SELECT pr.RoleID
, (SELECT ColumnName+','
FROM PageColumnSetting p3
WHERE p3.IsValid=1 AND p3.ParentID>0
AND NOT EXISTS(
SELECT 1 FROM PageColumnSetting p4
WHERE p4.IsValid=1 AND p4.ParentID=p3.ID
)
FOR XML PATH('')) AS ColumnStr
FROM PageColumnSetting p1
INNER JOIN PageRoleDim pr ON p1.ID=pr.ColumnID AND pr.IsValid=1
WHERE p1.IsValid=1 AND p1.ParentID>0
AND NOT EXISTS(
SELECT 1 FROM PageColumnSetting p2
WHERE p2.IsValid=1 AND p2.ParentID=p1.ID
)
GROUP BY pr.RoleID
)A
INNER JOIN dbo.[Role] r WITH(NOLOCK) ON A.RoleID=r.RoleID AND r.IsValid =1
3.FULL JOIN 将俩条数据合并为同一条数据
SELECT ISNULL(b1.TaskID,b2.TaskID) AS TaskID,ISNULL(b1.BookingID,b2.BookingID) AS BookingID, ISNULL(b1.BookingType,b2.BookingType) AS BookingType,
b1.OperationType AS PickOperationType,b1.FirstUpdateConfirmTime AS PickRollbackUpdateConfirmTime ,b1.FirstUpdateReasonType AS PickRollbackUpdateReason, --回退
b2.OperationType AS UnloadOperationType,b2.FirstUpdateConfirmTime AS PickUpdateConfirmTime ,b2.FirstUpdateReasonType AS PickUpdateReason --修改提货/卸货
FROM BookingRecordOperation b1
FULL JOIN BookingRecordOperation b2 ON b1.BookingID=b2.BookingID AND b1.TaskID=b2.TaskID AND b2.OperationType=2
AND b1.OperationType=1
2.Update
1.更新#PageData表中不存在的数据
UPDATE pd
SET pd.IsDump = 1
FROM #PageData pd
WHERE EXISTS(
SELECT 1
FROM dbo.DeliveryDetail dd WITH(NOLOCK)
WHERE dd.DeliveryNo = pd.DeliveryNo
AND dd.TotalNum <> dd.ResidueNum
AND dd.IsValid = 1
)
AND pd.CurrentOrgID = pd.SendOrgID
2.Update和INNER JOIN配合使用
UPDATE pd
SET pd.TotalVolume = a.TotalVolume,
pd.TotalWeight = a.TotalWeight,
pd.NumberOfUnits = a.NumberOfUnits,
pd.RevenueTon = dbo.GetRevenueTon(a.TotalVolume,a.TotalWeight)
FROM #PageData pd
INNER JOIN (
SELECT dt.DeliveryNo,
SUM(dt.ResidueNum) AS NumberOfUnits,
SUM((dt.Weight/dt.TotalNum)*dt.ResidueNum) AS TotalWeight,
SUM((dt.Volume/dt.TotalNum)*dt.ResidueNum) AS TotalVolume
FROM dbo.DeliveryDetail dt WITH(NOLOCK)
INNER JOIN #PageTemp pt ON pt.DeliveryNo = dt.DeliveryNo
WHERE dt.IsValid = 1
AND dt.TotalNum > 0
GROUP BY dt.DeliveryNo
) a ON a.DeliveryNo = pd.DeliveryNo
WHERE pd.DeliveryNo NOT IN(SELECT * FROM #XqDeliveryNo)
AND pd.SendOrgID = pd.CurrentOrgID
3.表/字段
新增表
create table tablename(col1 type1 [not null] [primary key],col2 type2 [not null],..)
删除表
drop table tablename
修改表
sp_rename tablename,newtablename //修改表名称
新增字段：
ALTER TABLE [表名] ADD [字段名] NVARCHAR (50) NULL
ALTER TABLE [表名] ADD [字段名] INT NOT NULL DEFAULT (0) //添加有默认值的
删除字段：
ALTER TABLE [表名] DROP COLUMN [字段名]
修改字段：
ALTER TABLE [表名] ALTER COLUMN [字段名] NVARCHAR (50) NULL
ALTER TABLE [表名] ADD DEFAULT [默认值] FOR [字段名] //修改默认值
4.索引(增删改查)
新增：
1、一般的创建语法：
CREATE (unique/cluster) INDEX<索引名> ON <表名>
【拓展】索引的类型有UNIQUE（唯一索引）、CLUSTERED（建立聚集索引）、NONCLUSTERED（建立非聚集索引）、Index_property（索引属性）。
UNIQUE索引既可以采用聚集索引结构，也可以采用非聚集索引的结构，如果不指明采用的索引结构，则SQL SERVER系统默认为采用非聚集索引结构。
删除：
1、一般的删除语法
drop index<索引名>
2、简要的删除语法
drop index [索引名]
3、删除某张表中的索引
drop index [索引名] ON [表名]
修改：
1、使用系统存储过程修改索引名称：
EXEC sp_rename [原名称],[新名称],[index]
【备注】sp_rename不止可以修改索引名称，同时可以修改表名、列名和类型名称。
查：
1、使用系统存储过程查询：
EXEC sp_helpindex [表名称]
2、使用系统的视图查询：
SELECT * FROM sysindexes WHERE name = ‘索引名称’
【常用的操作】
1、判断是否存在该索引，存在则删除
if exists(select * from sysindexes where name ‘soyn’)
drop index [soyn] on test1
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